Polymeric bags and method to make same

ABSTRACT

The present invention is directed to a bag of polymeric film and a method to make the bag. The bag can be comprised of a front panel and a rear panel. The front and rear panels can each be comprised of multiple layers of film. The bag can be formed from a collapsed bubble of polymeric film that has been folded in half so that opposing edges of the collapsed bubble form an opening of the bag. One of the layers of the folded bubble can be split adjacent to an edge of the collapsed bubble and a draw tape film can be inserted between the layers of the folded and collapsed bubble. The collapsed bubble can further be embossed by a pattern that can provide enhanced properties to bags formed from the folded bubble.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of pending application Ser. No.17/016,533, filed on Sep. 10, 2020, which is a divisional of applicationSer. No. 15/712,543, filed on Sep. 22, 2017. These two aforementionedapplications are hereby incorporated by reference into this disclosure.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to improvements in the construction andmanufacture of polymeric bags. In particular, the present inventionrelates to improvements to trash bags.

2. Description of the Related Art

Polymeric bags are ubiquitous in modern society and are available incountless combinations of varying capacities, thicknesses, dimensions,and colors. The bags are available for numerous applications includingtypical consumer applications such as long-term storage, food storage,and trash collection. Like many other consumer products, increaseddemand and new technology have driven innovations in polymeric bagsimproving the utility and performance of such bags. The presentinvention is an innovation of particular relevance to polymeric bagsused for trash collection.

Polymeric bags are manufactured from polymeric film produced using oneof several manufacturing techniques well-known in the art. The two mostcommon methods for manufacture of polymeric films are blown-filmextrusion and cast-film extrusion. In blown-film extrusion the resultingfilm is tubular while cast-film extrusion produces a generally planarfilm. Manufacturing methods for the production of drawstring bags from aweb of material are shown in numerous prior art references including,but not limited to, U.S. Pat. Nos. 3,196,757 and 4,624,654, which arehereby incorporated by reference. In blown film extrusion, the directionthat the film is extruded is commonly referred to as the machinedirection (MD) and the direction perpendicular to the machine directionis commonly referred to as the cross direction (CD).

Drawstring trash bags are frequently used in connection with rigidcontainers. When used with a rigid container, it is common to fold theupper opening of a drawstring trash bag over the upper rim of thecontainer to keep the upper opening of the bag accessible. Some rigidcontainers provide retaining devices to hold the upper opening of adrawstring bag in place while, in other instances, the drawstring bagmay provide certain features or properties that facilitate keeping thebag in place on the container. The use of these rigid containers isparticularly common in connection with 13-gallon drawstring bagstypically used in the household or in an office environment. Rigidcontainers may also be used with larger bags, such as those commonlyused for the collection of outdoor or yard waste. When drawstring bagsare used with supporting rigid containers, the drawstring trash bag isoften filled with trash and other debris until the capacity of thecontainer or trash bag is reached.

Use of polymeric film presents technical challenges since polymeric filmis inherently soft and flexible. Specifically, all polymeric films aresusceptible to puncture and tear propagation. In some instances, it maybe possible to increase the thickness of the film or select improvedpolymers to enhance the physical properties of the film. However, thesemeasures increase both the weight and cost of the polymeric film and maynot be practicable. In light of the technical challenges of polymericfilm, techniques and solutions have been developed to address the needfor improved shock absorption to reduce the likelihood of puncture andalso to increase the tear resistance of polymeric films.

U.S. Pat. No. 5,205,650, issued to Rasmussen and entitled Tubular Bagwith Shock Absorber Band Tube for Making Such Bag, and Method for itsProduction, discloses using polymeric film material with stretchablezones wherein the film material has been stretched in a particulardirection with adjacent un-stretched zones that extend in substantiallythe same direction. The combination of the stretched zones and adjacentun-stretched zones provides a shock absorber band intended to absorbenergy when the bag is dropped. Specifically, when a bag is dropped ormoved, the contents inside the bag exert additional forces that wouldotherwise puncture or penetrate the polymeric film. However, the shockabsorber bands absorb some of the energy and may prevent puncture of thefilm.

Another example of a polymeric film material designed to resist punctureis disclosed in U.S. Pat. No. 5,518,801, issued to Chappell and entitledWeb Materials Exhibiting Elastic-Like Behavior. Chappell, in theaforementioned patent and other related patents, discloses using aplurality of ribs to provide stretchable areas in the film much likeRasmussen. Chappell also discloses methods of manufacturing suchpolymeric film with such ribs.

Another example of shock absorption to prevent puncture is disclosed inU.S. Pat. No. 5,650,214 issued to Anderson and entitled Web MaterialsExhibiting Elastic-Like Behavior and Soft Cloth-Like Texture. Andersondiscloses using a plurality of embossed ribs defining diamond-shapedareas with a network of unembossed material between the diamond-shapedareas. Thus, the unembossed area comprises a network of straight, linearunembossed material extending in two perpendicular directions.

The foregoing disclosures specifically address the desire to increasethe shock absorption of polymeric film to reduce the likelihood ofpunctures occurring in the film. However, none of the foregoingdisclosures address the problem of reducing tear propagation in thepolymeric film of a bag.

Previously known solutions to limiting tear propagation are based on twoprimary concepts. First, longer and more tortuous tear paths consumemore energy as the tear propagates and can help in limiting the impactof the tear in a bag or polymeric film. Second, many polymeric films,particularly polymeric films made using a blown-film extrusion process,have different physical properties along different axes of the film. Inparticular, blown films are known to have higher tear strength in thecross-direction versus the corresponding tear strength in the machinedirection. Certain prior art solutions take advantage of thedifferential properties of polymeric films by redirecting tears into adifferent direction. This redirecting of tears can offer greaterresistance to a tear propagating. For example, some solutions redirect atear propagating in the weaker machine direction of blown film into thestronger cross-direction.

One solution for reducing tear propagation is based on the idea thatlonger, tortuous tear paths are preferable and is described in U.S. Pat.No. 6,824,856, issued to Jones and entitled Protective Packaging Sheet.Jones discloses materials suitable for packaging heavy loads byproviding an embossed packaging sheet with improved mechanicalproperties. Specifically, a protective packaging sheet is disclosedwhere surfaces of the sheet material are provided with protuberancesdisposed therein with gaps between protuberances. The protuberances arearranged such that straight lines necessarily intersect one or more ofthe protuberances. The resulting protective packaging sheet providesmechanical properties where tears propagating across the polymeric sheetare subject to a tortuous path. The tortuous path is longer, and morecomplex, than a straight-line tear, and a tear propagating along such apath would require markedly more energy for continued propagation acrossthe film compared to a tear along a similar non-tortuous path in thesame direction. Thus, due to the increased energy required for tearpropagation, the tortuous path ultimately reduces the impact of anytears that do propagate across the film.

Another example of a tear resistant plastic film is disclosed in U.S.Pat. No. 8,357,440 to George M. Hall with a filing date of Jun. 29, 2007and entitled Apparatus and Method for Enhanced Tear Resistance PlasticSheets, which is herein incorporated by reference into this disclosure.Hall discloses an alternative tortuous path solution and further relieson the fact discussed above that certain polymer films, particularlypolymeric films made in a blown-film extrusion process, are known tohave a stronger resistance to tear in the cross direction when comparedto the machine direction.

Hall discloses a solution that contemplates using preferably shapedembosses, particularly convex shaped embosses with a curved outerboundary, to provide maximum resistance to tear propagation. In mostpolymeric films, a tear will have a tendency to propagate along the pathof least resistance or in the machine direction. Hall contemplatesredirecting propagating tears in a tortuous path with the additionalintent of redirecting the machine direction tears along the curved edgesof the embossed regions and into a cross direction orientation. Theredirected tears in the cross direction will be subject to additionalresistance and, preferably, will propagate to a lesser degree than atear propagating in the machine direction in an unembossed film.

U.S. Pat. No. 9,290,303 to Brad A. Cobler (Cobler patent) with a filingdate of Oct. 24, 2013 and entitled Thermoplastic Films with EnhancedResistance to Puncture and Tear, herein incorporated by reference intothis disclosure, discloses use of an embossing pattern. This embossingpattern applied to polymeric film balances both properties of shockabsorption and tortuous tear paths in the cross direction. The patentdiscloses that the embossing pattern comprises a plurality of embossedregions comprised of a plurality of parallel, linear embosses. Theplurality of embossed regions is arranged so that a straight line cannottraverse the polymeric film without intersection at least one of theplurality of embossed regions.

Another method to improve the tear and puncture resistance of trash bagsmay be to construct the bag from multiple layers of polymeric film.Under certain conditions, two or more layers of film may provideimproved tear and strength properties in comparison to a single layer offilm with a comparable thickness. For instance, thinner layers of filmformed by blown film extrusion can lead to increased MD orientation dueto an increased draw down ratio. The increased MD orientation can resultin increased MD tensile strength and thus increase the burst strength ofbags formed from multiple layers of thin film versus a single layer offilm of comparable thickness.

An increased draw down ratio is also known to improve CD tear strengthdue to the increased MD orientation as may be the result of extrudingthinner layers of film. In contrast to this, the embossing pattern ofthe Cobler when applied to flex the film in the CD direction is known toimprove MD tear strength and decrease CD tear strength. Thus, the use ofmultiple layers of thin film can work in tandem with the embossingpattern of the Cobler applied to the film layers. The increased CD tearstrength of the thinner layers can offset the decrease in CD tearstrength due to use of the Cobler embossing pattern.

In light of the foregoing, it would be desirable to provide a method ofefficiently manufacturing bags comprised of panels having multiplelayers. It would also be desirable to provide trash bags with multiplelayers with the embossing pattern as disclosed by the Cobler patent. Abag with this pattern and multiple layers may provide a trash bag withimproved shock absorption and resistance to tear propagation incomparison to the state of the art trash bags. The present inventionaddresses these objectives.

SUMMARY OF THE INVENTION

In at least one embodiment of the present invention, a method to form abag of polymeric film is disclosed. To form the bag, a tube of polymericfilm can be formed and the tube can have a machine direction. The tubecan be collapsed to form a collapsed tube. The collapsed tube cancomprise first and second layers and opposing first and second edges.Each of the layers can have first and second halves on opposing sides ofa central axis of the collapsed tube. The collapsed tube can be foldedsuch that the first edge is positioned adjacent to the second edge. Thefolding of the collapsed tube can define a third edge generallycoextensive with a central axis of the collapsed tube. The first andsecond halves of the first layer and the first and second halves of thesecond layer can be sealed to each other by a plurality of seals. Thecollapsed tube can be formed into a plurality of bags. Each bag of theplurality of bags can comprise a front panel and a rear panel. The frontpanel can comprise the first half of the first and second layers. Therear panel can comprise the second half of the first and second layers.

In certain embodiments of the above-described method, the first half ofthe first layer can be slit to form two inner edges. One of the twoinner edges can be positioned to expose an inner surface of the secondlayer. A first draw tape can be inserted between the first and secondlayers and adjacent to the two inner edges. One of the two inner edgescan be positioned over the first draw tape. A first inner seal can beformed in the first and second layers adjacent to a first edge of thetwo inner edges. Additionally, a second inner seal in the first andsecond layers can be formed adjacent to the second edge of the two inneredges.

The above-described method may further include the two inner edges slitadjacent and parallel to the first edge. The first and second halves ofthe second layer can be positioned between the first and second halvesof the first layer. The two inner edges can comprise upper and lowerinner edges and the upper inner edge can be positioned between the lowerinner edge and the first edge. The first inner seal can be positionedbetween the first edge and the upper inner edge. The first draw tape canbe positioned between the first inner seal and the first edge.

In further embodiments of the above-described method, the first edge canbe folded back towards the third edge to define a fourth edge and afirst overlap section. A first hem can be defined between the firstoverlap section and the front panel. The second edge can be folded backtowards the third edge to define a fifth edge and a second overlapsection. A first hem can be defined between the first overlap sectionand the first layer and a second hem can be defined between the secondoverlap section and first layer. A draw tape can be inserted into thefirst hem and the second hem. The first overlap section can be sealed tothe first layer with a first hem seal and the second overlap section canbe sealed to the first layer with a second hem seal. Additionally, thefirst hem seal can seal the first and second layers of the front panelto the first and second layers of the overlap section. A plurality ofclosely spaced pairs of parallel seals can be formed in the tubeextending in a cross direction. A perforation can be formed between andparallel to each pair of parallel seals. The tube can be separated ateach perforation to form the plurality of bags.

In further embodiments of the method disclosed above, an embossedpattern can be embossed onto the collapsed tube. The collapsed tube canbe embossed prior to the collapsed tube being folded. The embossedpattern can be applied to at least two partial widths of the collapsedtube and not applied to at least three partial widths of the collapsedtube.

In a further embodiment of the present invention, an additional methodis disclosed to form a bag from a tube of blown polymeric film. The tubecan have a machine direction. The tube can be collapsed to form acollapsed tube. The collapsed tube can have first and second layers andopposing first and second edges. The collapsed tube can further havefirst and second halves defined on opposite sides of a central axis ofthe collapsed tube. The collapsed tube can be folded to position thefirst edge adjacent to the second edge and to form a third edge about acentral axis of the collapsed tube. The first half of the first layercan be slit to form two detached sections. One of the two detachedsections can be positioned to expose an inner surface of the secondlayer. A first draw tape can be inserted between the first and secondlayers. One of the two detached sections can be positioned over thefirst draw tape. The two detached sections can be attached to the secondlayer. The first and second halves of the first layer and the first andsecond halves of the second layer can be sealed to each other by a firstside seal and a second side seal. The collapsed tube can be separatedinto a plurality of bags.

In the above-discussed embodiment of the invention, the method canfurther include the first draw tape located between the first and secondlayers and adjacent to the two inner edges. The two detached sectionscan be attached to the second layer via a heat seal. The two detachedsections can include two inner edges parallel to the first outer edge. Aplurality of pairs of closely spaced parallel seals can be formed thatextend in the cross direction. A perforation can be formed between andparallel to each pair of parallel seals. The collapsed tube can beseparated at each perforation to form the plurality of bags.

In a further embodiment of the invention, a bag can be formed from acollapsed tube of polymeric film. The bag can have a front panel andrear panel. The front and rear panels can be joined adjacent to a firstside edge by a first side seal and adjacent to an opposite second sideedge by a second side seal. The front panel and the rear panel can bejoined at a bottom edge. The bottom edge can be formed by folding thecollapsed tube such that the bottom edge is generally coextensive with acentral axis of the collapsed tube. An opening of the bag can be definedby an upper edge of the front and rear panels. The upper edge can bedefined by opposing first and second edges of the collapsed tube.

In the above-discussed embodiment of the invention, the front panel canfurther include first and second layers. The first and second layers canextend from the upper edge to the bottom edge. A first drawstring can bebetween the first and second layers of the front panel and extendgenerally from the first side seal to the second side seal. The firstand second inner edges can be defined in the first layer of the frontpanel and below the upper edge. The first inner edge can be above thesecond inner edge. A first inner seal can be above the first inner edgeand below the upper edge. A second inner seal can be below the secondinner edge. The first drawstring can be between the upper edge and thefirst inner seal. The first side seal can seal together the first andsecond layers of the front panel, the first drawstring, first and secondlayers of an overlap section of the front panel, first and second layersof the rear panel, a second drawstring, and first and second layers ofthe overlap section of the rear panel.

BRIEF DESCRIPTION OF THE RELATED DRAWINGS

A full and complete understanding of the present invention may beobtained by reference to the detailed description of the presentinvention and certain embodiments when viewed with reference to theaccompanying drawings. The drawings can be briefly described as follows.

FIG. 1 provides a top view of a collapsed tube of a first embodiment ofthe present invention.

FIGS. 2A-2E provide cross-sectional views of the collapsed tubeaccording to the first embodiment of the present invention.

FIG. 2F provides a cross-section view of the collapsed tube according toa second embodiment of the present invention.

FIG. 3A provides a top view of the collapsed tube of FIG. 2E.

FIG. 3B provides a partial cross-sectional schematic view of thecollapsed tube of FIG. 3B taken from partial cutting plane D-D.

FIG. 4 provides a perspective view of a bag according to the firstembodiment of the present invention.

FIG. 5 provides a front view of the bag of FIG. 4 .

FIG. 6A provides a cross-sectional view of the collapsed tube accordingto a third embodiment of the present invention.

FIG. 6B provides a cross-sectional view of the collapsed tube accordingto a fourth embodiment of the present invention.

FIG. 7A provides a top view of the collapsed tube of FIG. 6A.

FIG. 7B provides a partial cross-sectional schematic view of FIG. 7Aalong the partial cutting plane of C-C.

FIG. 8 provides a perspective view of a bag according to the thirdembodiment of the present invention.

FIG. 9 provides a front view of the bag of FIG. 8 .

FIG. 10 provides a top view of a collapsed tube according to a fifthembodiment of the present invention.

FIG. 11 provides a perspective view according to the fifth embodiment ofthe present invention.

FIG. 12 provides a top schematic view of an embossing pattern accordingto the fifth embodiment of the present invention.

FIG. 13 provides an additional top view of the collapsed tubeillustrating further the fifth embodiment of the present invention.

FIG. 14 provides a perspective view of the bag according to the fifthembodiment of the present invention.

FIG. 15 provides a side view of the bag of FIG. 14 .

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure illustrates several embodiments of the presentinvention. It is not intended to provide an illustration or encompassall embodiments contemplated by the present invention. In view of thedisclosure of the present invention contained herein, a person havingordinary skill in the art will recognize that innumerable modificationsand insubstantial changes may be incorporated or otherwise includedwithin the present invention without diverging from the spirit of theinvention. Therefore, it is understood that the present invention is notlimited to those embodiments disclosed herein. The appended claims areintended to more fully and accurately encompass the invention to thefullest extent possible, but it is fully appreciated that certainlimitations on the use of particular terms are not intended toconclusively limit the scope of protection.

FIG. 1 shows a top view of a flattened or collapsed tube 100 of blownpolymeric film formed by a blown film extrusion process. FIG. 1 furthershows the tube having a machine direction (MD) in the direction thattube 100 is extruded and a cross direction (CD) perpendicular to themachine direction. FIG. 1 shows the flattened tube 100 with a first edge110 on a first side of tube 100 and an opposing edge 112 on a secondside of tube 100. Central axis A of tube 100 is shown extending in themachine direction of tube 100. FIG. 1 further shows first and secondhalves 106 and 108 of tube 100 on opposing sides of central axis A.

In certain embodiments of the present invention, tube 100 may becomprised of a polymer blend, the polymer blend generally having linearlow density polyethylene (LLDPE) as the primary component, but otherpolymers may be utilized including, but not limited to, otherpolyethylene polymers such as high density polyethylene (HDPE) or lowdensity polyethylene (LDPE). Typically, the primary component of thepolymer blend, such as linear low density polyethylene (LLDPE), willcomprise at least 75% of the polymer blend. The remaining portion of thepolymer blend may include additives including, but not limited to,coloring additives, anti-blocking agents, and/or odor control additives.

FIGS. 2A-2E illustrate various steps of a method of forming tube 100into a multilayer bag. Typically, tube 100 shown in FIGS. 2A-2E would becompletely flat with the first and second layers generally having littleor no space between the two layers. However, first and second layers 102and 104 are shown with a certain amount of separation for ease ofillustration. Also for ease of illustration, the thickness of thepolymeric film of tube 100 is illustrated with a single line throughoutthis disclosure.

FIG. 2A shows tube 100 in a generally flattened configuration. FIG. 2Afurther shows tube 100 having a first layer 102 and a second layer 104.Tube 100 is further shown in FIGS. 1 and 2A with a first half 106 and asecond half 108. The first half 106 encompasses half of the first andsecond layers and the second half 108 encompasses half of the first andsecond layers of tube 100.

Once tube 100 is formed and collapsed as shown in FIG. 2A, collapsedtube 100 can be folded in half as illustrated in FIG. 2B. For ease ofillustration, FIGS. 2B-2E are not in proportion with FIG. 2A. Forinstance, the overall width of tube 100 shown in FIGS. 2B-2E would beone-half the overall width of tube 100 shown in FIG. 2A ifproportionality was maintained.

As shown in FIG. 2B, with collapsed tube 100 folded in half, first andsecond edges 110 and 112 are positioned adjacent to each other.Furthermore, a third edge 114 is defined in tube 100 opposite from edges110 and 112. With tube 100 folded in half, third edge 114 is coextensivewith central axis A of tube 100 of FIG. 1 . Due to the folding, firsthalf 106 of tube 100 is shown located above and adjacent to second half108 of tube 100 such that first and second halves 104 a and 104 b ofsecond layer 104 are proximate to each other and in between first andsecond halves 102 a and 102 b of first layer 102.

As shown by FIG. 2C, first layer 102 can be slit or severed in the firsthalf 102 a adjacent to the first edge 110 and in the machine direction.Second half 102 b can also be slit adjacent to the second edge 112 withthe slit extending in the machine direction. The slits in the first andsecond halves 102 a and 102 b can form first and second inner edges 116and 118 in the first half 102 a and third and fourth inner edges 120 and122 in the second half 102 b of the first layer 102. The inner edges116, 118, 120, and 122 can extend in the machine direction and beparallel with first and second edges 110 and 112 as shown by FIG. 3A.

As further shown by FIG. 2C, first and second detached sections 115 and117 in the first half 102 a of tube 100 and third and fourth detachedsections 121 and 123 in the second half 102 b of tube 100 can be definedby the slitting operation. Once the two layers are slit, first and thirdedges 116 and 120, along with first and third detached sections 115 and121, can be positioned away from the second layer 104 by rotating orfolding first and third detached sections 115 and 121 away from secondand fourth inner edges 118 and 122.

As shown by FIG. 2D, once first and third detached sections 115 and 121are moved, draw tape 128 can then be inserted between first and secondlayers 102 and 104. FIG. 2D further shows first and second inner seals124 and 126 sealing second detached section 117 to second layer 104 andfourth detached section 123 to second layer 104. Second inner seal 124is shown proximate to second inner edge 118 and fourth inner seal 126 isshown proximate to fourth inner edge 122. Seals 124 and 126 may beformed before or after draw tape 128 is inserted. In at least certainembodiments of the invention, seals 124 and 126, and any othersubsequently discussed seals, may be formed by heat-sealing the layersof polymeric film; however, other methods may be used to form the sealsof the disclosure, such as pressure sensitive adhesive.

In certain embodiments of the present invention, draw tape 128 may beconstructed from the same film as tube 100. However, in otherembodiments, the material of draw tape 128 may differ from the materialused for tube 100. For instance, draw tape 128 may be constructed from apolymeric film comprising a blend of LLDPE and LDPE. In furtherembodiments of the present invention, the draw tape may be constructedfrom film comprising HDPE or a blend of HPDE with one or both of LLDPEand LDPE. Other polymers may also be utilized in the construction ofdraw tape 128, such as polypropylene. As with the film of tube 100, thedraw tape film may include additives such as coloring additives,anti-blocking agents, and/or odor control additives.

As shown by FIG. 2E, once draw tape 128 is inserted between layers 102and 104, first and third detached sections 115 and 121 can be folded orrotated towards second layer 104 and sealed to second layer 104 by thirdand fourth inner seals 130 and 132. Third and fourth inner seals 130 and132 can be located adjacent to first and third inner edges 116 and 120.As further shown by FIG. 2E, a first hem 125 can be defined by detachedsection 115, first half 104 a of second layer 104 and third inner seal130. Additionally, a second hem 127 can be defined by detached section121, second half 104 b of second section 104, and fourth inner seal 132.

In certain embodiments of the present invention, tube 100 may be slit atleast two inches away from first and second edges 110 and 112 toconstruct first and second hems 125 and 127 with a width of at least twoinches. Thus, a typical draw tape 128 with a width of generally one inchmay be accommodated in two hems 125 and 127.

FIG. 2F illustrates a further embodiment of the invention, which isshown not to scale in comparison to FIG. 2E for purposes ofillustration. The embodiment of FIG. 2F is similar to the embodimentillustrated by FIGS. 2C-2E; however, rather than slits placed in firstlayer 102, slits are placed in the FIG. 2F embodiment in first andsecond halves 104 a and 104 b of second layer 104. This modificationresults in first and second detached sections 115 and 117 and first andsecond inner ends 116 and 118 defined in first half 104 a of innersecond layer 104. This location of the slitting operation furtherresults in third and fourth detached sections 121 and 123 and first andsecond inner ends 120 and 122 defined in second half 104 b of innersecond layer 104. Thus, detached sections 115, 117, 121, and 123 aresealed to outer first layer 102, rather than inner second layer 104, byinner seals 124, 126, 130, and 132 as previously described for FIG. 2E.

FIG. 3A shows a top view of collapsed tube 100 of FIG. 2E, whichillustrates additional steps for converting tube 100 into a plurality ofbags. For instance, FIG. 3A shows a plurality of pairs of closely spacedseals 140 formed in tube 100 with seals 140 extending in the crossdirection of tube 100. As shown by FIG. 3A, the two seals of each pairof seals 140 are closely spaced in relation to each other. In betweeneach pair of closely spaced seals 140 is shown a perforation 142extending in the cross direction from the first and second edges 110 and112 to the third edge 114. Each seal of the pair of closely spaced seals140 forms a side seal for a bag formed from tube 100. Each perforation142 may be severed to define one of two side edges of an individual bag.

Each seal 140 seals together first halves 102 a and 104 a of the firstand second layers 102 and 104 to second halves 102 b and 104 b of firstand second layers 102 and 104 to seal together four layers of tube 100.Furthermore, as shown by FIG. 3B, a schematic partial cross-sectionalview of FIG. 3A, six layers of film are sealed together by each seal 140when the film of draw tape 128 is taken into account. FIG. 3B shows thateach seal 140 seals together first layer of first half 102 a, draw tape128 within first half 106, second layer of first half 104 a, draw tape128 within second half 108, and first layer 102 b of the second half.

Now returning to FIG. 3A, first inner edge 116 is shown above the secondinner edge 118 and the first inner edge 116 is shown between the secondinner edge 118 and first edge 110. Draw tape 128 is shown between thefirst edge 110 and the first inner edge 116. Third inner seal 130 isshown between first edge 110 and first inner edge 116 and first innerseal 124 is shown below second inner edge 118.

Now turning to FIGS. 4 and 5 , an individual bag 200 is shown. Bag 200can be formed from tube 100 according to the method illustrated by FIGS.2A-2E and 3 . FIG. 4 shows a front panel 200 a and a rear panel 200 b ofbag 200 while FIG. 5 shows only front panel 200 a. Further shown inFIGS. 4 and 5 are opposing side edges 142 a and 142 b of bag 200 formedfrom perforations 142 as shown in FIG. 3A. First and second edges 110and 112 of tube 100 form the top edges of bag 200 while third edge 114forms a bottom edge of bag 200. Seals 140 of FIG. 3A form opposing firstand second side seals 140 a and 140 b in bag 200. Seals 124 and 130 ofFIG. 3A define lower and upper hem seams in front panel 200 a and seals126 and 132 define lower and upper hem seams in rear panel 200 b. Drawtape 128, once severed by perforations 142, forms drawstrings 128 a inbag 200. Hem 125 is shown defined in front panel 200 a. Bag 200 canfurther have drawstring cutouts 150 for a user to access drawstring 128a as shown by FIGS. 4 and 5 .

FIGS. 6A-6B and 7-9 illustrate further embodiments of the invention. Theembodiments of FIGS. 6A-6B and 7-9 forms a multilayer bag from flattenedtube 100 as previously discussed for FIGS. 1-5 . However, rather thanslitting and inserting draw tape film as described for FIGS. 2C-2E, thefolded over flattened tube 100 of FIG. 2B is used to construct adrawstring bag by folding back edges 110 and 112 to form hems forencapsulating a draw tape.

As shown in FIG. 6A, first and second edges 110 and 112 of tube 100 canbe folded back towards opposite third edge 114 of tube 100. In at leastone embodiment, edges 110 and 112 are folded towards the first layer 102of tube to form first and second overlap sections 145 and 147. Thefolding of edges 110 and 112 forms fourth and fifth outer edges 144 and146 in tube 100 which are located opposite from third edge 114. Asfurther shown by FIG. 6A, a first hem seal 160 can be placed in firstoverlap section 145 and first tube half 106. Additionally, a second hemseal 162 can be placed into second overlap section 147 and second half108 of tube 100.

FIG. 6A further shows a first overlap hem 164 defined by the firstoverlap section 145, the first tube half 106 and the first hem seal 160.Additionally, a second overlap hem 166 is defined by the second overlapsection 147, the second half 108, and second hem seal 162. Prior to theformation of the hem seals 160 and 162, draw tape 128 can be insertedinto hems 164 and 166. FIG. 6A also shows that first hem seal 160 sealstogether the first and second layers 102 and 104 of the first overlapsection 145 to the first and second layers 102 and 104 of first tubehalf 106. Application of first and second hem seals 160 and 162 resultsin overlap sections 145 and 147 contacting directly first surface 102 oftube 100 at first and second halves 102 a and 102 b. Additionally, thesecond hem seal 162 seals together the first and second layers 102 and104 of the second overlap section 147 to the first and second layers 102and 104 of the second tube half 108. Seal 160 can also seal the firstlayer of the first half 102 a to the second layer of the first half 104a and seal 162 can seal the first layer of the second half 102 b to thesecond layer of the second half 104 b.

FIG. 6B illustrates a further embodiment of the invention that issimilar to the FIG. 6A invention. However, rather than first and secondends 110 and 112 being folded towards outer first layer 102 as shown inFIG. 6A, FIG. 6B shows first and second edges 110 and 112 folded towardsinner second layer 104. Thus, first overlap section 145 is in directcontact with first half 104 a of second layer 104 at first hem seal 160and second overlap section 147 is in direct contact with second half 104b of second layer 104 at second hem seal 162. Reference is made to thediscussion of FIG. 6A for further discussion of the FIG. 6B embodimentdue to shared construction of the two embodiments.

Now turning to FIG. 7A, steps for converting collapsed tube 100 of FIG.6A into a plurality of bags is illustrated. As previously discussed forthe FIG. 3A embodiment, the plurality of pairs of closely spaced seals140 can be placed in tube 100 with seals 140 extending in the crossdirection. In between each pair of seals 140 can be placed perforation142. Each seal of the pair of closely spaced seals 140 forms a side sealfor a bag formed from tube 100. Each perforation 142 may be severed toform a plurality of individual bags. Reference is made to the discussionof FIG. 6A for the additional features shown by FIG. 7A.

Now examining FIG. 7B, a schematic partial cross-sectional view is shownwhich illustrates the multiple layers of film sealed together by eachseal 140 of FIG. 7A at hems 164 and 166. FIG. 7B shows that each one ofseals 140 seals together first and second layers 102 a and 104 a of thefirst overlap section 145, the first draw tape 128 of the first overlapsection 145, first and second layers 102 a and 104 a of the first half106 of tube 102, first and second layers 102 b and 104 b of the secondhalf 108 of tube 100, draw tape 128 of the second overlap section 147,and first and second layers 102 b and 104 b of the second overlapsection 147. Thus, each one of the seals 140 results in ten layers offilm sealed together at hems 164 and 166.

Shown in FIGS. 8 and 9 is an individual bag 300 formed from tube 100 ofFIGS. 6 and 7A. FIG. 8 shows a front panel 300 a and a rear panel 300 bof bag 300 while FIG. 9 shows only front panel 300 a. The structure offront and rear panels of bag 300 is identical. FIGS. 8 and 9 showopposing side edges 142 a and 142 b of bag 300 formed from perforations142 of FIG. 7A. The fourth and fifth outer edges 144 and 146 of tube 100of FIG. 7A form the top edges of bag 300. Seals 140 of FIG. 7A formopposing first and second side seals 140 a and 140 b in bag 300. Seal160 defines a first hem seal in front panel 300 a and seal 162 defines asecond hem seal in rear panel 300 b. Draw tape 128, once severed byperforations 142, forms drawstring 128 a in bag 300. Hem 164 is showndefined in front panel 300 a of bag 300. Bag 300 is further shown withdrawstring cutouts 150 to provide access to drawstrings 128 a.

In certain embodiments of the invention, it may be desirable to emboss apattern into the film of tube 100. FIGS. 10 and 11 shows tube 100 withembossing pattern 600 applied to tube 100. This embossing pattern ofFIGS. 10 and 11 is discussed in detail in the Cobler patent referencedin the Background of the Invention. As applied to tube 100, the patternallows the flattened tube 100 to expand in the cross direction. Whentube 100 is converted into bags as previously discussed, the crossdirection corresponds to the lengthwise direction of the bags such thatas additionally debris are loaded into the bags, the bags may expand andgrow in height. This embossing pattern may also provide a certain amountof adhesion between the first and second layers 102 and 104 of tube 100;however, as one skilled in the art would understand, the embossing oftube 100 is not expected to bond the layers together under typicalprocess conditions.

Shown in FIG. 12 is a detailed schematic view of the embossed pattern asillustrated generally in FIGS. 11 and 13-15 . The embossed pattern 600has a plurality of embossed regions 610, each embossed region 610 havinga generally hexagonal shape with each embossed region 610 separated by acontinuous unembossed arrangement 620. One of the hexagonal shapes isindicated by dashed lines B in FIG. 12 . The dashed lines of B are shownfor reference only and form no structure of the disclosed invention.Each embossed region 610 is shown as defined by nine parallel andadjacent linear embosses 630. The two opposing horizontally extendingsides of each embossed region 610 is defined by three middle adjacentparallel linear embosses 630 with equal length; each horizontal side ofthe hexagon formed by adjacent ends of the three linear embosses 630.Each of the other four diagonal sides of the hexagon can be defined byan endpoint of an outer emboss of the three middle adjacent linearembosses 630 and adjacent end points of three other outer adjacentlinear embosses 630. Each of the three other adjacent linear embosses630 can decrease in length the same amount as the adjacent linear emboss630.

The hexagonal shaped embossed regions 610 of FIG. 12 can be orientedsuch that opposing vertices of each hexagon are at a left and right sideof each hexagon as illustrated in FIG. 12 . Adjacent to the vertices canbe two short opposing, linear embosses 630 at each end of each embossedregion 610. These opposing vertices encourage each embossed region tofold-in when the linear embosses unfold in the horizontal direction.Hence, a film with the embossed pattern 600 of FIG. 12 expands in thehorizontal direction but not in vertical direction. This expansion ismuch greater and at a much lower force than would be required to stretchthe unembossed film.

Methods of forming the embossing pattern of FIG. 12 is further discussedin U.S. Patent Appl. Publ. No. 2017/0113872 to Brad A. Cobler andassigned to Poly-America, L.P., filed on Jan. 4, 2017, which is herebyincorporated by reference. The embossing pattern 600 in FIG. 12 is shownoriented at 90 degrees in relation to the embossing pattern 600 as shownin FIGS. 10-11 and 13-15 .

Now returning to FIGS. 10 and 11 , the embossing pattern may not beapplied to an entire width of tube 100, the width extending in the crossdirection of tube 100 from first to second edges 110 and 112 of tube100. Rather, pattern 600 may be applied in a plurality of partialwidths, such as first and second partial pattern widths 600 a and 600 b,which result in a plurality of unembossed partial widths 602. While theembossing pattern 600 is not applied to the entire width of tube 100,FIGS. 10 and 11 shows the embossing pattern 600 extending continuouslyin the machine direction on tube 100.

It may be desirable to not emboss certain sectional widths of tube 100for various reasons. For instance, it may desirable not to emboss apartial width that is coextensive with central axis A of tube 100 so asnot to interfere with the folding of tube 100. Additionally, if thebottom edge of the resultant bags is defined by central axis A, it maydesirable to not emboss this location to alleviate the risk ofimproperly formed embossing patterns resulting in liquid leaking frombags formed from tube 100. Furthermore, partial widths adjacent to firstand second edges may not be embossed so as not to interfere with theformation of the hem in the upper area of a resultant bag and to providean area of the bag for a user to grasp without the flexing due to thedisclosed embossing pattern.

As shown in FIGS. 11 , these partial widths may be formed byintermeshing rollers 404 and 406. Upper roller 404 may have theembossing pattern defined about its circumference. However, bands of itscircumference may have the pattern removed with the diameter of thesebands slightly less than the width of roller 404 due to the absence ofthe pattern. FIG. 11 shows first, second, third un-patterned bands, 404a, 404 c, and 404 e with the pattern not defined on the surface ofroller 404. Further shown are patterned bands 404 b and 404 d with thepattern defined on roller 404. Alternatively, a length of roller 404 maysimply be shorter than the width of tube 100 such that an area adjacentto first and second edges 110 and 112 of tube 100 are not embossed.

As further shown by FIG. 11 , when flattened tube 100 passes through nip408 of rollers 404 and 406, the embossing pattern on the rollers isformed onto tube 100. As a result, first and second embossed sections600 a and 600 b are formed, as shown by FIGS. 10 and 11 , which definefirst, second, and third unembossed sections 602 a, 602 b, and 602 c.

In a particular embodiment, the width of flattened tube 100 can be 48inches. Furthermore, the width of first unembossed section 602 a betweenfirst edge 110 of tube 100 and outer edge 600 a 1 of first embossedsection 600 a, as shown by FIGS. 10 and 11 , can be approximately fiveinches. The width of second unembossed section 602 b between second edge112 of tube 100 and outer edge 600 b 1 of second embossed section 600 bcan also be approximately five inches. Additionally, the width of thethird unembossed section 602 c between first and second inner edges 600a 2 and 600 b 2 of first and second embossed sections 600 a and 600 b,as further shown by FIGS. 10 and 11 , can be approximately four inches.Thus, the width of each embossed section, first and second embossedsections 600 a and 600 b, can be approximately seventeen inches.

Once tube 100 is embossed as illustrated by FIG. 11 , the tube can befolded as previously discussed regarding FIG. 2 b . Draw tape 128 can beinserted into the embossed tube of FIG. 11 as previously illustrated byFIGS. 2C-2E. FIG. 13 shows tube 100 after undergoing the steps of FIGS.2C-2E, as discussed above. The tube of FIG. 13 shares the same structureof previously discussed tube 100 of FIG. 3A; however, the FIG. 13embodiment further includes embossed section 600 a, as discussed forFIG. 11 . Furthermore, the previously discussed dimensions of unembossedsections 602 a and 602 c and embossed section 600 a can be the same asdiscussed above for FIG. 11 . Thus, with tube 100 folded in half, thedistance from second edge 114 of tube 100 to inner edge 600 a 2 of firstembossed section 600 a, one-half the width of third unembossed section602 c, can be approximately two inches. Furthermore, the distance fromfirst edge 110 to outer edge 600 a 1 of first embossed section 600 a,the width of first unembossed section 602 a, can be approximately fiveinches as previously discussed.

FIGS. 14 and 15 illustrate drawstring trash bag 400 formed by the methodillustrated by FIGS. 2C-2E and 10-13 . Bag 400 of FIGS. 14 and 15 sharesthe same construction as that of bag 200 of FIGS. 4 and 5 except for theaddition of embossing pattern 600 of FIG. 12 by the method illustratedby FIGS. 10-11 and 14 . Bag 400 includes a partial length of embossedsection 600 a. Further shown is a partial length of first and thirdunembossed sections 602 a and 602 c. Reference is made to the discussionof FIGS. 4 and 5 regarding the features of bag 400 shown by FIGS. 14 and15 not addressed here due to the similar construction of theembodiments.

As previously noted, the specific embodiments depicted herein are notintended to limit the scope of the present invention. Indeed, it iscontemplated that any number of different embodiments may be utilizedwithout diverging from the spirit of the invention. Therefore, theappended claims are intended to more fully encompass the full scope ofthe present invention.

We claim:
 1. A bag formed from a collapsed tube of polymeric film, thecollapsed tube extruded in a machine direction, the bag comprising:front and rear panels, the front and rear panels joined to each otheralong opposing first and second side edges, the first and second edgesextending generally in a cross direction, the cross directionperpendicular to the machine direction, the front and rear panels eachhaving separate outer and inner layers of polymeric film, the front andrear panels joined at a bottom edge, the bottom edge extending generallyin the machine direction, an upper edge opposite the bottom edge, anopening of the bag defined about the upper edge, first and second inneredges defined in the inner layer of the front panel and below the upperedge, the first and second inner edges extending generally in themachine direction, a first drawstring between the inner and outer layersof the front panel, the first drawstring between the upper edge and thefirst inner edge, the first drawstring extending generally in themachine direction, the first inner edge above the second inner edge, thefirst inner edge below a bottom end of the first drawstring, a gapbetween the first inner edge and the second inner edge, the second inneredge proximate to the first inner edge, the bottom edge defined by afold in the inner and outer layers of the front and rear panels, and thegap less than a height of the first drawstring.
 2. The bag of claim 1further comprising: the first drawstring extending generally from thefirst side edge to the second side edge, and the first inner edgeproximate to the bottom end of the first drawstring.
 3. The bag of claim1 further comprising: a first inner seal above the first inner edge andbelow the first drawstring, the first inner seal extending generally inthe machine direction, and a second inner seal below the second inneredge, the second inner seal extending generally in the machinedirection.
 4. The bag of claim 1 further comprising: a first side sealjoining the front and rear panels to each other proximately along thefirst side edges and a second side seal joining the front and rearpanels to each other proximately along the second side edges, the firstand second side seals, and the first and second side edges generallyparallel to each other.
 5. The bag of claim 4 further comprising: thefirst and second side seals sealing together the inner and outer layersof the front and rear panels, the first drawstring, and a seconddrawstring.
 6. A bag formed from a collapsed tube of polymeric film, thecollapsed tube extruded in a machine direction, the bag comprising:front and rear panels, the front and rear panels joined to each otheralong first and second side edges, the side edges extending generally ina cross direction, the cross direction perpendicular to the machinedirection, the front and rear panels each having outer and inner layersof polymeric film, the front and rear panels joined at a folded bottomedge, an upper edge opposite the bottom edge, an opening of the bagdefined about the upper edge, first and second inner edges defined inthe inner layer of the front panel and below the upper edge, a firstdrawstring between the inner and outer layers of the front panel, thefirst drawstring between the upper edge and the first inner edge, thefirst inner edge above the second inner edge, the first inner edge belowa bottom end of the first drawstring, and a gap between the first inneredge and the second inner edge, the gap having a distance less than aheight of the first drawstring.
 7. The bag of claim 6 furthercomprising: the first inner edge proximate to the first drawstring andthe second inner edge proximate to the first inner edge.
 8. The bag ofclaim 6 further comprising: a first inner seal above the first inneredge and below the upper edge, a second inner seal below the secondinner edge, and the firsts and second inner seals extending generally inthe machine direction.
 9. The bag of claim 6 further comprising: thefirst and second inner edges extending generally in the machinedirection, and the upper edge generally parallel to the bottom edge. 10.The bag of claim 6 further comprising: the first drawstring extendinggenerally from the first side edge to the second side edge, and thefirst inner edge proximate to the bottom end of the first drawstring.11. The bag of claim 6 further comprising: a first side seal joining thefront and rear panels to each other proximately along the first sideedges and a second side seal joining the front and rear panels to eachother proximately along the second side edges.
 12. The bag of claim 11further comprising: the first and second side seals each sealingtogether the inner and outer layers of the front and rear panels, thefirst drawstring, and a second drawstring.
 13. A bag formed from acollapsed tube of polymeric film, the collapsed tube extruded in amachine direction, the bag comprising: front and rear panels, the frontand rear panels joined to each other along opposing first and secondside edges, the front and rear panels each having outer and inner layersof polymeric film, the front and rear panels joined at a bottom edge, anupper edge opposite the bottom edge, an opening of the bag defined aboutthe upper edge, the upper edge defined in both the front and rearpanels, first and second inner edges defined in the inner layer of thefront panel and below the upper edge, a first drawstring between theinner and outer layers of the front panel, the first drawstring betweenthe upper edge and the first inner edge, the first inner edge above thesecond inner edge, the first inner edge below a bottom end of the firstdrawstring, a gap between the first inner edge and the second inneredge, the bottom edge formed by a fold in the front and rear panels, thebottom edge extending generally in the machine direction, the first andsecond inner edges extending generally in the machine direction, and thegap less than a height of the first drawstring.
 14. The bag of claim 13further comprising: the first drawstring extending generally from thefirst side edge to the second side edge in the machine direction, andthe first inner edge proximate to the bottom end of the firstdrawstring.
 15. The bag of claim 13 further comprising: the first inneredge proximate to the bottom end of the first drawstring, the secondinner edge proximate to the first inner edge, a first inner seal abovethe first inner edge and below the upper edge, and a second inner sealbelow the second inner edge.
 16. The bag of claim 13 further comprising:a first side seal joining the front and rear panels to each otherproximately along the first side edges and a second side seal joiningthe front and rear panels to each other proximately along the secondside edges.
 17. The bag of claim 16 further comprising: the first andsecond side seals sealing together the inner and outer layers of thefront and rear panels, the first drawstring, and a second drawstring.18. The bag of claim 13 further comprising: a drawstring cutout definedalong the upper edge between the first and second side edges.